Safety-lock.



O. A. MULLER.

SAFETY LOOK.

APPLICATION FILED APRA, 1910.

Patented July 9, 1912.

i g I I CARL AUGUST M't TLLER, 0F WITZENHAUSEN, GERMANY.

SAFETY-LOCK.

Specification of Letters Patent.

Entented July 9, 191.2.

Original application filed September 9, 1907. Serial No. 391,672. Divided and this application filed. April 4, 1910. Serial No. 553,383.

To all w/zom. it may concern.

Be it known that l, Cami Aiious'r Mi'inmni, a subject of the llmperor of (iermany, residing at \Yitzenhausen, Germany, have in vented certain new and useful Improvements in Safety-tanks. of which the following is a specification. v

This safety lock is of the class described in my application Serial No. 391,672, filed on the 9th September 1907, (the present case being a division of said application,) in which the key disappears in the lock during the closing, or is completely countersunk in the lock. According to the application in question, the key sunk into the lock is, however, used as a coupling link between the handle of the lock and its nut, while in the lock according to this invention, the handle is rigidly secured to the nut. This lock which is specially suitable for money safes, offers a greater safety against tmauthorized opening by means of various tools, such as skeleton keys, pick-locks, etc., owing to the tumblers being mounted in the cylindrical bodv rotatable by means of the handle iu such manner that when the cylindrical body is rotated. they describe a circle about the center of the said body. In that Way, it is possible to arrange on the said circle further separate locking devices either in the cylindrical body or in the casing of the lock, which prevent complete rotation of the body (such as required for opening the lock), unless the key bringing about the proper adjustment ot' the tumblers is used. Moreover. owing to this arrangement of the tumblers and to the complete sinking of the key in the lock, the keyhole is closed inside by the cylindrical rotating body during the locking, so that nobody can get by means of skeleton keys or the like to the tumblers, or to the devices locking therewith during the locking operation.

The accompanying drawing shows in Figures 1 and 2 such a lock in vertical section before the closing and after the introduction of the key. Fig. 3 is afront elevation of the lock, while Fig. 4 is a cross-section on line CC of Fig. 3.

The cylindrical rotatable plug 9 is provided on the one hand with the handle d used for closing, and on the other hand it is secured to the roll-back b of the lock by means of the pin- 2". In the plug 1 are arranged the tumblers Z controlled 4 by springs m and pressed toward the key hole in the groove '11. of the casing 0. Th y lock, therefore, the plug g on one side. On the other side it is locked by the counter tumblers Z mounted in the casing u and pressed by springs on into the recess of the plug in which the tumblers I move. For the purpose of locking, both the tumblers Z and the coun ter tumblers Z are moved by the key f in such manner that. they release the plug for the purpose of rotation. in order to obtain a proper adjustment of the tumblers, the key is forced into the keyhole by means of a presser or driver c pivotally mounted on the casing 12. The key engages then with its two projections f into the corresponding recesses f f of the plug g, so that its outer edge is flush with the surface of the atter. The result is that during the subsequent locking, that is to say, during the rotation of the plug 1 by means of the handle (I, the key f disappears in the casing o and is pushed out again by the spring-controlled tumblers only when a complete revolution of the plug 9 is effected. During the rotation of the plug 7, the tumblers Z, together with the key, describe a circle about the center of the plug 1. On the said circle, inside the casing 0 are provided, as shown in Fig. 3, grooves n n c0rres].)onding to the tumblers Z, for the purpose of stopping the, motion of the plug 9 when the tumblers are not. properly adjusted. In the same way, further counter-tumblcrs I may be provided in the casing 0, which also lock the plug f/ in the bearings of the tumblers I when the latter are not properly adjusted.

For indicating that the plug 7 has the proper position required for introducing the key, that is to say, the position in which the tumblers are opposite the keyhole, the plug 1 is provided with two rounded off pins 9 pressed by a. spring into recesses of the easing 0, corresponding to their rounded ott' portion. In that way they slightly brake the. movement of the plug without preventing it altogether from rotating. The reserve grooves n n are provided so that it the tumblers should have been adjusted by means of pick-locks or similar tools, the plug rotated past the groove 01, and the pick-locks or the like withdrawn, then the tumblers would be caught in the reserve grooves. As the proper key is provided with project-ions f and is therefore wider at its outer end than the reserve grooves n of, it can easily slide over these grooves without being caught therein.

What I claim as my invention and desire to secure by Letters Patent is 1. In a safety lock, a casing, a rotatable cylindrical plug mounted therein, a handle provided on one side of said plug, a r0ll-' back towhich said plug is attached on the other side, tumblers in said plug, counter tumblers in said casing adapted to engage said plug, a key adapted to rotate with said plug in said casing about the axis of r0- t-ation of said plug and to release said tum{ blers, which latter are moved parallelly to the axis of rotation of the plug and when being locked describe with the key a circle around said axis of rotation, and meanswhereby said tumblers are adapted when incorrectly adjusted to engage from the rear with the front Wall of the casing to lock the plug.

' 2. In a safety look, a casing having looking grooves in the front wall thereof, and provided with a keyhole, said grooves not being accessible from the keyhole, a rotatable cylindrical plug mounted in said casing,'a handle provided on one side of said plug, a roll-back to which said plug is attached on the other side, tumblersin said plug adapted to engage from the rear with said locking grooves, counter-tumblers in said casing adapted to engage said plug, and a key adapted to rotate with said plug in said casing about the center of said plug and to release said tumblers.

3. In a safety look, a casing having looking grooves therein and provided with a key hole, a cylindrical plug mounted in said casing and adapted to be rotated to cover said keyhole, a handle provided on one side of said plug, a roll-back to which said plug is attached on the other side, tumblers in said plug adapted to engage with said locking grooves one of which is of such width that said tumblers lock with it when incorrectly adjusted and when theplug has cov ered the key hole, counter-tumblers in said casing adapted to engage said plug, and a key adapted to rotate with said plug in said casing about the center of the plug and to release said tumblers.

4. In a safety look, a casing having locking grooves therein and provided with a key hole, a cylindrical plugmounted in said casing and adapted to be rotated to cover said key-hole, a handle provided on one side of said plug, a roll-back to which said plug isattached on the other. side, tumblers in said plug adapted to engage with said CARL AUGUST MI ILLER.

Witnesses SOPHIE Mt'JLLER, ALDO HAASE. 

